The present invention relates to a four-wheel drive unit for a toy vehicle and, more particularly, to a windup spring four-wheel drive unit for a toy vehicle, which is capable of always properly transmitting a drive force from front and rear wheels to the ground even when the front and the rear axles are twisted in their axial direction.
A variety of interesting conventional four-wheel drive toy vehicles such as a toy automobile have been heretofore developed. Such four-wheel drive toy vehicles may be run on a rough road or an off road in the same manner as a real four-wheel drive vehicle. These toy vehicles are full of interest and bring much enjoyment to their users.
In the conventional four-wheel drive toy vehicles, although a four-wheel drive mechanism together with a proper suspension mechanism similar to those of the actual four-wheel drive vehicle can be employed in a large-sized toy vehicle, in a small-sized toy vehicle such as a so-called mini toy vehicle, such complicated mechanisms can not be used and the front and the rear axles are rotatably fixed to a chassis of the toy vehicle. Accordingly, in this case, the four wheels are always positioned in a flat plane regardless of how rough the surface of a road is. Hence, when the front wheel axle is twisted with reference to the rear wheel axle by so-called rolling, the drive force cannot be properly transmitted from the four wheels to the ground.